Semiconductor device and fabrication method thereof

ABSTRACT

A semiconductor device includes a lower wiring layer made of a conductive material; an upper wiring layer formed in an upper layer than the lower wiring layer; and a fuse film, at least a portion of the fuse film being formed in a plug formation layer in which a plug for connecting the lower wiring layer and the upper wiring layer is formed, and made of a conductive material including a metallic material other than copper.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application Nos. 2011-24389 and 2011-24390, respectivelyfiled on Feb. 7, 2011, the entire contents of which are incorporatedherein by reference.

TECHNICAL FIELD

The present disclosure relates to a semiconductor device in which a fuseis formed within a multilayer wiring structure, and a fabrication methodthereof.

BACKGROUND

A semiconductor device such as a semiconductor memory, or the like, mayhave a fuse in a metal wiring layer. The fuse can be configured to becut by irradiating laser light or applying a current of a thresholdvalue or higher. The characteristics of an electronic circuit assembledin a semiconductor device may be adjusted (trimmed) or a defectiveportion within the semiconductor device may be separated by selectivelycutting the fuse. In general, a fuse is provided in a metal wiring layerand made of the same material as that of a metal wiring.

Aluminum (Al) has been widely used as a wiring material, and recently,wiring resistance is required to be reduced, particularly in a powersemiconductor device which consumes a great amount of power. Thus, astructure of a semiconductor device using copper (Cu) having higherconductivity than that of Al, as a wiring material, has been proposed.That is, a fuse made of copper may be formed in the copper wiring layer.

However, when the fuse is cut by laser light or the like, fragments ofcopper constituting the fuse scatter within the wiring structure. Copperis easily spread within silicon oxide, which is a material commonly usedin an interlayer insulating layer, so it may reach an element regionformed on the semiconductor substrate and may likely negatively affectan element operation. Further, a fuse made of copper can easily corrodeat a surface that is exposed when the fuse is cut. This corrosion mayreach the vicinity of the semiconductor substrate through a current pathconnected to the fuse.

SUMMARY

The present disclosure provides some embodiments of a semiconductordevice, and fabrication method(s) thereof, including a wiring layer madeof copper as a main ingredient and having at least one fuse, thesemiconductor device have characteristics for preventing degradationdespite the fuse being cut.

According to some embodiments, provided is a semiconductor device,including a lower wiring layer made of a conductive material including,for example, copper as a main ingredient; an upper wiring layer formedin an upper layer than the lower wiring layer; and a fuse film, at leasta portion of the fuse film being formed in a plug formation layer inwhich a plug for connecting the lower wiring layer and the upper wiringlayer is formed, and made of a conductive material including a metallicmaterial, for example other than copper, as a main ingredient.

The semiconductor device has a multilayer wiring structure in which alower wiring and an upper wiring, each being made of copper as a mainingredient, for example, are connected by a plug formed in the plugformation layer. In some embodiments, at least a portion of the fusefilm is formed in the plug formation layer, and the fuse film is made ofa conductive material including metal, other than copper, as a mainingredient. Thus, when the fuse film is cut, fragments of the copper donot scatter, so the semiconductor device is not broken down andoperational characteristics thereof are not degraded. Further, since thefuse film is made of a metallic material other than copper, a cutportion thereof will hardly corrode. Thus, a breakdown of thesemiconductor device or a degradation of operational characteristicsthereof resulting from corrosion starting from the fuse film can berestrained or prevented. In this manner, the semiconductor device whichhas the wirings using copper as a main ingredient and hascharacteristics which are not degraded when cutting the fuse can beprovided.

In some embodiments, the upper wiring is made of a conductive materialincluding a metal other than copper, as a main ingredient.

The semiconductor device further includes a fuse plug formed in the plugformation layer to connect the fuse film and the upper wiring layer andmade of a conductive material including a metallic material, other thancopper, as a main ingredient, for example.

With this configuration, the fuse film may be electrically connected tothe upper wiring layer, with a fuse plug interposed therebetween. Thus,the fuse film may be connected to an internal circuit within thesemiconductor device with the upper wiring layer interposedtherebetween. The fuse plug may be made of a conductive materialincluding a metallic material other than copper as a main ingredient,for example. Thus, although the fuse plug is exposed when the fuse filmis cut, corrosion does not start from the fuse plug. Accordingly, thesemiconductor device may have a structure in which a breakdown or adegradation of characteristics thereof resulting from the fuse isminimized.

In some embodiments, the semiconductor device further includes acapacitor obtained by stacking a lower electrode layer, an insulatinglayer, and an upper electrode layer. The upper electrode layer may beconfigured as a metallic layer in an upper layer than the lower wiringlayer, and the fuse film may include a first metal layer made of thesame material as that of the upper electrode layer, the first metallayer being in a same layer as the upper electrode layer.

With this configuration, the fuse film may be formed by using the firstmetal layer made of the same material in the same layer as the upperelectrode layer of the capacitor. That is, the fuse film may be formedthrough the same process as that of the upper electrode layer of thecapacitor. Thus, since the fuse film can be formed through a smallernumber of processes, an increase in fabrication costs can be restrained.

In the semiconductor device, the fuse film may include a second metallayer made of the same material as that of the fuse plug, and the secondmetal layer may be in a same layer as the fuse plug.

With this configuration, the fuse film may be formed by using the secondmetal layer made of the same material in the same layer as that of thefuse plug. That is, the fuse film may be formed through the same processas that of the fuse plug. Thus, since the fuse film can be formedthrough a smaller number of processes, an increase in fabrication costscan be restrained.

With this configuration, in some embodiments, the fuse plug and thesecond metal layer (the fuse film) may be integrally formed, and neednot be formed separately. Thus, the manufacture of the semiconductordevice may be simplified or more efficient.

In some embodiments, the fuse plug and the second metal may beseparated. That is, a pair of fuse plugs may be in contact with firstand second regions of the fuse film, and the second metal layer may beformed in a third region of the fuse film. In this case, the first tothird regions may be separated regions, and the third region positionedbetween the first and second regions.

The semiconductor device may further include a sealing member (forexample, made of a metallic material including copper as a mainingredient) formed to have a container-like shape to surround the fusefilm when viewed from a plane of the semiconductor device.

With this configuration, in some embodiments, since the fuse film issurrounded by the sealing member having the container-like shape, and acrack is formed starting from the fuse when the fuse is cut. Spreadingof the crack can be restrained to the interior of the sealing member.Accordingly, the multilayer wiring structure can be protected, whereby abreakdown or a degradation of characteristics of the semiconductordevice can be restrained or prevented.

According to other embodiments, provided is a method for fabricating asemiconductor device, including: forming a lower wiring layer made of aconductive material including copper as a main ingredient, for example;forming a plug formation layer on the lower wiring layer; forming a fusefilm made of a conductive film including a metal, other than copper, asa main ingredient in the plug formation layer, for example; forming anopening for an interlayer connection plug and an opening for a fuse plugin the plug formation layer; burying a conductive material including ametal, other than copper, as a main ingredient, for example, in theopening for then interlayer connection plug and the opening for the fuseplug, and coupling the fuse plug to the fuse film; and forming an upperwiring layer connected to the fuse plug and the interlayer connectionplug in an upper layer than the plug formation layer.

With this method, in some embodiments, since the interlayer connectionplug and the fuse plug are formed through the same process, thesemiconductor device having the structure capable of restraining orpreventing a breakdown or a degradation of the characteristics resultingfrom the fuse film can be fabricated through a smaller number ofprocesses.

In the method, in some embodiments, the forming the fuse film comprisesforming a capacitor structure including a lower electrode film, aninsulating film, and an upper electrode film at an upper layer than thelower wiring layer, and simultaneously forming a first metal layer madeof the same metallic material as that of the upper electrode film in asame layer as the upper electrode film.

With this method, in some embodiments, the first metal film constitutingthe fuse film can be simultaneously formed in the process of forming theupper electrode film of the capacitor. Accordingly, the semiconductordevice can be fabricated through a smaller number of processes.

In the method, in some embodiments, an opening for forming the fuse filmis simultaneously formed when forming the opening for the interlayerconnection plug and the opening for the fuse plug, and the burying theconductive material comprises forming a second metal layer (a portion ofthe fuse film) by burying a metal having the same material as that ofthe interlayer connection plug in the opening for forming the fuse filmsuch that it constitutes at least a portion of the fuse film.

With this method, in some embodiments, the second metal layerconstituting the fuse film can be simultaneously formed through theprocess of forming the plug. Accordingly, the semiconductor device canbe fabricated through a smaller number of processes.

In the method, the opening for the fuse (or fuse opening) may be formedin a region within a first metal layer formation region when viewed fromthe plane.

With this method, in some embodiments, etching for forming the fuseopening can be stopped at the first metal layer, whereby a filmthickness of the second metal layer constituting the fuse film can beaccurately controlled. When the first metal layer is not formed, ifetching conditions for the opening for the plug (or plug opening) toreliably reach the lower wiring layer are determined, the fuse openingbecomes deeper than the film thickness required for the fuse film. Forthis reason, the fuse film has a film thickness more than necessary.Thus, for example, when the fuse film is cut (fusion cutting) by laserprocessing, a required laser light output is increased. Accordingly,when the first metal layer is previously formed and the fuse opening isformed by the first metal layer, the film thickness of the second metallayer can be controlled to have a sufficient thickness as necessary.

According to other embodiments, provided is a semiconductor deviceincluding: a semiconductor substrate; a copper fuse; a sealing layerdisposed between the semiconductor substrate and the copper fuse, theseal layer being made of a copper layer; a wiring layer formed on anupper layer than the copper fuse, the wiring layer having a firstportion and a second potion which are connected to a first portion and asecond portion of the copper fuse, respectively, the wiring layer beingmade of a metallic layer that includes a metallic material other thancopper; and a copper sealing member coupled to the sealing layer andformed to have a container-like shape to surround the copper fuse.

In some embodiments, the semiconductor device further includes: anexternal connection layer formed in a same layer as the wiring layer.The external connection layer is made of the same material as the wiringlayer.

In some embodiments, the semiconductor device further includes: aplurality of copper wiring layers, wherein the copper fuse is formed ina same layer as an uppermost layer among the plurality of copper wiringlayers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial sectional view of a semiconductor device, accordingto some embodiments.

FIG. 2 is a partial plan view of the configuration illustrated in FIG.1.

FIG. 3A is a sectional view showing a method for fabricating thesemiconductor device, according to some embodiments.

FIG. 3B is a sectional view showing a subsequent process of FIG. 3A.

FIG. 3C is a sectional view showing a subsequent process of FIG. 3B.

FIG. 3D is a sectional view showing a subsequent process of FIG. 3C.

FIG. 3E is a sectional view showing a subsequent process of FIG. 3D.

FIG. 3F is a sectional view showing a subsequent process of FIG. 3E.

FIG. 4 is a sectional view for explaining the configuration of a majorpart of a semiconductor device, according to some embodiments.

FIG. 5A is a sectional view for explaining a method for fabricating thesemiconductor device, according to some embodiments.

FIG. 5B is a sectional view showing a subsequent process of FIG. 5A.

FIG. 5C is a sectional view showing a subsequent process of FIG. 5B.

FIG. 6 is a sectional view for explaining the configuration of a majorpart of a semiconductor device, according to some embodiments.

FIG. 7A is a sectional view showing a method for fabricating thesemiconductor device, according to some embodiments.

FIG. 7B is a sectional view showing a subsequent process of FIG. 7A.

FIG. 7C is a sectional view showing a subsequent process of FIG. 7B.

FIG. 7D is a sectional view showing a subsequent process of FIG. 7C.

FIG. 7E is a sectional view showing a subsequent process of FIG. 7D.

FIG. 7F is a sectional view showing a subsequent process of FIG. 7E.

FIG. 8 is a partial sectional view of a semiconductor device, accordingto some embodiments.

FIG. 9 is a partial plan view of the configuration illustrated in FIG.8.

FIG. 10A is a sectional view showing a method for fabricating thesemiconductor device, according to some embodiments.

FIG. 10B is a sectional view showing a subsequent process of FIG. 10A.

FIG. 10C is a sectional view showing a subsequent process of FIG. 10B.

FIG. 10D is a sectional view showing a subsequent process of FIG. 10C.

FIG. 10E is a sectional view showing a subsequent process of FIG. 10D.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. In the followingdetailed description, numerous specific details are set forth in orderto provide a thorough understanding of the present subject matter.However, it will be apparent to one of ordinary skill in the art thatthe present subject matter may be practiced without these specificdetails. In other instances, well-known methods, procedures, systems,and components have not been described in detail so as not tounnecessarily obscure aspects of the various embodiments.

FIG. 1 is a partial sectional view of a semiconductor device, accordingto some embodiments, and FIG. 2 is a partial plan view of theconfiguration illustrated in FIG. 1. The semiconductor device includes asemiconductor substrate 1, a multilayer wiring structure 2 formed on asurface of the semiconductor substrate 1, and a passivation film(surface protective layer) 3 for covering the multilayer wiringstructure 2. The semiconductor substrate 1 may be a silicon substrate. Asemiconductor element (not shown) may include an active element such asa transistor or the like, and may be formed in a surface layer portionthereof. The multilayer wiring structure 2 includes first to ninthinterlayer insulating layers 11 to 19, first to seventh etching stoplayers 21 to 27, first to fourth metal wirings 31 to 34, a fuse film 4,and uppermost layer wirings 5. The passivation film 3 may be formed of,for example, a nitride film (silicon nitride film) and covers thesurface of the uppermost layer wiring 5.

In some embodiments, the multilayer wiring structure 2 includes asealing member 6 having a container-like shape (e.g., squarecontainer-like shape) surrounding the fuse film 4 when viewed from theplane. Further, in some embodiments, a capacitor 7 may be formed on themultilayer wiring structure 2.

In the multilayer wiring structure 2, the first interlayer insulatinglayer 11, the first etching stop layer 21, the second interlayerinsulating layer 12, the second etching stop layer 22, the thirdinterlayer insulating layer 13, the third etching stop layer 23, thefourth interlayer insulating layer 14, the fourth etching stop layer 24,the fifth interlayer insulating layer 15, the fifth etching stop layer25, the sixth interlayer insulating layer 16, the sixth etching stoplayer 26, the seventh interlayer insulating layer 17, the seventhetching stop layer 27, the eighth interlayer insulating layer 18, acapacitive film 70, and the ninth interlayer insulating layer 19 aresequentially stacked in this order on the surface of the semiconductorsubstrate 1. The interlayer insulating layers 11 to 19 are made of, forexample, SiO₂. Further, the etching stop layers 21, 23, 25, and 27 aremade of, for example, SiCN. The etching stop layers 22, 24, and 26 areconfigured as stacked films of, for example, SiC and SiCN. Thecapacitive film 70 is made of, for example, SiN or SiCN.

The first metal wiring 31 may be formed in the same wiring layer (firstmetal wiring layer) as the second interlayer insulating layer 12. Thesecond metal wiring 32 may be formed in the same wiring layer (secondmetal wiring layer) as the fourth interlayer insulating layer 14. Thethird metal wiring 33 may be formed in the same wiring layer (thirdmetal wiring layer) as the sixth interlayer insulating layer 16. Thefourth metal wiring 34 may be formed in the same wiring layer (fourthmetal wiring layer) as the eighth interlayer insulating layer 18. Thefirst to fourth metal wirings 31 to 34 are wirings (e.g., copperwirings) made of a conductive material using copper as a mainingredient, for example.

The first to fourth metal wirings 31 to 34 may be buried in wiringrecesses formed in each of the second, fourth, sixth, and eighthinterlayer insulating layers 12, 14, 16, and 18, respectively. Morespecifically, the first metal wiring 31 may be buried in a wiring recessformed in the second insulating layer 12 by a damascene process. Thefirst metal wiring 31 may be electrically connected to an element (afunctional element such as a transistor element or the like) formed onthe surface of the semiconductor substrate 1, via a plug 30 buried inthe first insulating layer 11. The plug 30 may be made of, for example,tungsten (W). A barrier metal layer 39 (e.g., made of Ta) may beinterposed between the plug 30 and the first interlayer insulating layer11. Further, the second to fourth metal wirings 32 to 34 may be buriedin the wiring recesses formed in the fourth, sixth, and eighthinterlayer insulating layers 14, 16, and 18, and also, they are buriedin vias (holes) formed in the third, fifth, and seventh interlayerinsulating layers 13, 15, and 17, through a dual damascene process. Thesecond to fourth metal wirings 32 to 34 may be electrically connected tothe immediately underlying metal wirings 31, 32, and 33, respectively. Abarrier metal layer 36 may be formed on inner wall surfaces of thewiring recesses and the vias in order to prevent copper from spreading.The first to fourth metal wirings 31 to 34 using copper as a mainingredient may be disposed in a region surrounded by the barrier metallayer 36 and the etching stop layers 22, 24, and 26. The etching stoplayers 21, 23, 25, and 27 may be layers for stopping etching performedon the interlayer insulating layers 12, 14, 16, and 18 to form thewiring recesses. Also, the etching stop layers 22, 24, and 26 may belayers for stopping etching performed on the interlayer insulatinglayers 13, 15, and 17 to form the vias.

As shown in FIG. 2, in some embodiments, two fuse films 4 may bedisposed in parallel when viewed from the plane of the semiconductor andformed to have a linear shape (band shape), respectively. These fusefilms 4 may electrically connect the uppermost layer wirings 51 and 52(5) and the uppermost layer wirings 53 and 54 (5), respectively. Morespecifically, the uppermost wirings 51 and 53 are connected to one endof each of the fuse films 4, and the uppermost layer wirings 52 and 54are connected to the other end of each of the fuse films 4. The fusefilms 4 may be formed in a plug formation layer 10 in which a plug 9 forconnecting the uppermost layer wiring 5 (upper wiring layer) to theunderlying fourth metal wiring 34 (lower wiring layer) is formed. Theplug formation layer 10 may be a layer in which the ninth interlayerinsulating layer 19 is formed.

One side or both sides of the uppermost layer wiring 51 and 52 connectedto one fuse film 4 may be connected to an internal circuit of thecorresponding semiconductor device. Similarly, one side or both sides ofthe uppermost layer wirings 53 and 54 connected to another fuse film 4may be connected to the internal circuit of the correspondingsemiconductor device. When the fuse film 4 is not cut, the pair ofuppermost layer wirings connected to the corresponding fuse film 4 maybe electrically connected, and when the fuse film 4 is cut, theelectrical connection between the pair of uppermost layer wiringsconnected to the corresponding fuse film 4 may be electricallydisconnected. In this manner, the characteristics of an electroniccircuit assembled in the semiconductor device may be adjusted, or adefective portion within the semiconductor device may be separated.

The fuse film 4 includes a first metal film 41 (first metal layer)formed on the capacitive film 70 and a second metal film 42 (secondmetal layer) formed on the first metal film 41. A barrier metal layer 43may be formed between the first metal film 41 and the second metal film42 to prevent the metal material of the second metal film 42 fromspreading. The barrier metal layer 43 constitutes a portion of the fusefilm 4. More specifically, a recess corresponding to the shape of thefuse film 4 may be formed in the ninth interlayer insulating layer 19 atan upper side of the first metal film 41. A side wall (a side wall ofthe ninth interlayer insulating layer 19) and a lower surface (a surfaceof the first metal film 41) of this recess are covered by the barriermetal layer 43. The second metal film 42 may be disposed within therecess covered by the barrier metal layer 43. The second metal film 42also serves as a fuse plug for connecting the fuse film 4 to theuppermost layer wiring 5 (51 to 54). That is, the second metal film 42is integrally formed with a fuse plug.

When viewed from the plane, the first metal film 41 may be formed in alarger area (in some embodiments, an area having an elongatedrectangular shape corresponding to the shape of the fuse film 4) thanthe second metal film 42 and the barrier metal layer 43, and the secondmetal film 42 and the barrier metal layer 43 are within the formationregion of the first metal film 41, without a protrusion from theformation region of the corresponding first metal film 41. That is, whenviewed from the plane, the second metal film 42 and the barrier metallayer 43 have edges at a position inwardly retreated from the edge ofthe first metal film 41. In some embodiments, the edges of the secondmetal film 42 and the barrier metal layer 42 and the edge of the firstmetal film 41 are spaced apart at a substantially equal interval overthe entire circumference.

The first metal film 41 is made of a conductive material that includes ametal other than copper, e.g., TiN, as a main ingredient. Also, thesecond metal film 42 is made of a conductive material that includes ametal material other than copper, e.g., tungsten (W), as a mainingredient. Further, the barrier metal layer 43 may be configured, forexample, as a stacked film formed by sequentially stacking Ta, TaN, Ti,and TiN on the first metal film 41.

The uppermost layer wiring 5 includes, for example, a main body portion5 a, a barrier layer 5 b stacked below the main body portion 5 a, and asurface metal film 5 c stacked at an upper side of the main body portion5 a. The main body portion 5 a may be made of a conductive material thatincludes a metal (e.g., aluminum) other than copper, e.g., AlCu, as amain ingredient, the barrier layer 5 b is formed, for example, as astacked film of Ti and TiN sequentially stacked from a lower side, andthe surface metal film 5 c is made of, for example, TiN.

As shown in FIG. 2, the sealing member may be formed to have acontainer-like shape (in some embodiments, a square container-likeshape) surrounding the fuse film 4 when viewed from the plane, and isconfigured by forming the first to fourth metal wirings 31 to 34 in anannular shape (in some embodiments, a square annular shape). Annularvias 61 to 64 are formed to have an annular shape under the first tofourth annular metal wirings 31 and 34 constituting the sealing member 6such that they correspond to the first to fourth metal wirings 31 to 34.The second to fourth metal wirings 32 to 34 may be formed to bury theimmediately underlying annular vias 62 to 64. Further, an annular metalplug 37 may be buried in the annular via 61 immediately under the firstmetal wiring 31. In some embodiments, the annular metal plug 37 may beconnected to a polysilicon wiring layer 38 formed on the semiconductorsubstrate 1. The polysilicon wiring layer 38 may be formed, for example,on the same layer as that of the polysilicon electrode constituting atransistor gate electrode formed on the semiconductor substrate 1. Theannular metal plug 37 may be made of, for example, tungsten (W). Abarrier metal layer 39 (e.g., made of Ta) is interposed between theannular metal plug 37 and the first interlayer insulating layer 11.

The capacitor 7 includes a lower electrode 71 (lower electrode layer), acapacitive film 70, and an upper electrode 72 (upper electrode layer).The lower electrode 71 and the upper electrode 72 face each other withthe capacitive film 70 interposed therebetween, forming a capacitorstructure. The lower electrode 71 may be configured as a portion of thefourth metal wiring 34. The capacitive film 70 may be formed on thefourth metal wiring 34 and the eighth interlayer insulating layer 18.The upper electrode 72 may be formed of a metal film on the same layeras the first metal film 41 of the fuse film 4. The lower electrode 71may be connected to the uppermost wiring layer 56 (5) with a plug 91 (9)interposed therebetween, and the upper electrode 72 may be connected tothe uppermost wiring layer 57 (5) with a plug 92 (9) interposedtherebetween. The capacitive film 70 is etched by using the upperelectrode 72 and the first metal film 41 as masks, so a film thicknessimmediately below the upper electrode 72 and the first metal film 41 isgreater than that of other portions. The lower electrode 71 may belarger than the upper electrode 72, and has a protrusion extending fromthe upper electrode 72 when viewed from the plane. At the protrusion,the plug 91 may be connected to the lower electrode 71 through thecapacitive film 70.

An opening 46 for an electrical connection (e.g., connection by wirebonding) with respect to the surface of the uppermost layer wiring 5 isformed in the passivation film 3. A portion exposed from the opening 46in the uppermost layer wiring 5 is a pad 47 to be electrically connectedwith the outside. Further, an annular opening 48 may be formed at aposition immediately above the sealing member 6 in the passivation film3. The annular opening 48 divides the passivation film 3 into aninternal region and an external region of the sealing member 6 whenviewed from the plane. Further, a recess portion 49 may be formed bymaking the passivation film 3 thin in a region (in some embodiments, arectangular region extending over middle portions of two fuse films 4)including an immediately upper portion of the middle portion of the fusefilm 4. The recess portion 49 may be formed simultaneously during anetching process for forming the openings 46 and 48. The recess portion49 may be used, for example, as a process window for cutting the fusefilm 4 (fusion cutting) through laser processing. When the fuse film 4is cut by the laser processing or the like, and when a crack occurs inthe passivation film 3 in the recess portion 49, the crack can bestopped by the annular opening 48, without being spread to thepassivation film 3 at the outer side.

In this manner, in the semiconductor device according to someembodiments, at least a portion of the fuse film 4 can be formed on theplug formation layer 10 and the fuse film 4 can be made of a conductivematerial including metal other than copper as a main ingredient. Thus,when the fuse film 4 is cut, fragments of copper do not scatter, so thesemiconductor device is not broken down and operational characteristicsthereof are not degraded. In addition, since the fuse film 4 is made ofa metallic material other than copper, a cut section is hardly corroded.Thus, a breakdown or a degradation of operational characteristics of thesemiconductor device resulting from corrosion starting from the fusefilm 4 can be restrained or prevented. In this manner, the semiconductordevice which includes the wirings using copper as a main ingredient andhas characteristics which are not degraded when cutting the fuse occurs.

Additionally, in some embodiments, the first metal film 41 made of thesame material on the same layer as that of the upper electrode 72 of thecapacitor 7 constitutes a portion of the fuse film 4. For this reason,as explained later, the fuse film 4 can be formed through the sameprocess as that of the upper electrode 72. Thus, since the fuse film 4can be formed through a smaller number of processes, an increase infabrication costs can be restrained.

Further, in some embodiments, the fuse film 4 includes the second metalfilm 42 made of the same material as that of the plug 9 on the samelayer as that of the plug 9. For this reason, as explained later, thefuse film 4 can be formed through the same process as that of the plug9. Thus, since the fuse film can be formed through a smaller number ofprocesses, an increase in fabrication costs can be restrained. Further,in some embodiments, since the second metal film 42 is also used as afuse plug, there is no need to additionally form a fuse plug. Thus, thefabrication of the semiconductor device can be further facilitated.

Further, the sealing member 6 may be installed to have thecontainer-like shape to surround the fuse film 4 when viewed from theplane. For this reason, although a crack occurs starting from the fusefilm 4 when the fuse film 4 is cut, spreading of the crack can berestrained within the sealing member 6. Accordingly, multilayer wiringstructure 2 can be protected, and thus, a breakdown or a degradation ofoperational characteristics of the semiconductor device can berestrained or prevented.

FIGS. 3A to 3F are sectional views sequentially showing a process of amethod for fabricating the semiconductor device, according to someembodiments, in which a process after the formation of the capacitivefilm 70 is illustrated.

As shown in FIG. 3A, the fourth metal wiring 34 is buried in the eighthinterlayer insulating layer 18 and planarized, e.g., through chemicalmechanical polishing (CMP), and then, the capacitive film 70 is formedon the planarized surface. The capacitive film 70 can be made of, forexample, an insulating material that can prevent, for example, copper(Cu) such as SiN or SiCN from spreading. The capacitive film 70 may beformed to cover the surfaces of the eighth interlayer insulating layer18 and the fourth metal wiring 14 through, for example, plasma chemicalvapor deposition (CVD). Thereafter, an electrode film 81 constitutingthe upper electrode 72 and the first metal film 41 may be stacked on thecapacitive film 70. The electrode film 81 may be made of, for example,TiN, and formed through a sputtering method.

Next, as shown in FIG. 3B, a resist 82 having a pattern corresponding tothe upper electrode 72 and the first metal film 41 is formed, and theelectrode film 81 is etched by using the resist 82 as a mask. Thisetching may be executed until the electrode film 81 in the regionexposed from the resist 82 is completely removed. For this reason, inthe region exposed from the resist 82, the capacitive film 70 notcovered by the upper electrode 72 and the first metal layer 41 isslightly etched (up to the middle of the film thickness). Accordingly,the upper electrode 72 and the first metal film 41 are formed, and thecapacitive film 70 positioned immediately under the upper electrode 72and the first metal film 41 is relatively thick while other regionsbecome relatively thin. Thereafter, the resist 82 is removed.

Next, as shown in FIG. 3C, the ninth interlayer insulating layer 19 maybe formed. The ninth interlayer insulating layer 19 may be made of, forexample, SiO₂, and may be formed through plasma CVD.

Next, as shown in FIG. 3D, a resist 83 having openings corresponding tothe plug opening 66 for a fuse and contact plug openings 67 and 68 maybe formed. The ninth interlayer insulating layer 19 may be etched by theetching using the resist 83 as a mask, and accordingly, the fuse plugopening 66 and the contact plug openings 67 and 68 penetrating the ninthinterlayer insulating layer 19 are formed. The fuse plug opening 66 maybe positioned in an internal region of the first metal film 41 whenviewed from the plane, and the contact plug opening 68 may be positionedin an internal region of the upper electrode 72 when viewed from theplane. Thus, etching of the ninth interlayer insulating layer 19 isstopped at the first metal film 41 and the upper electrode 72. Further,in the contact plug opening 67, etching of the ninth interlayerinsulating layer 19 is stopped at the capacitive film 70. That is, thefirst metal film 41, the upper electrode 72, and the capacitive film 70serve as etching stop layers. After the ninth interlayer insulatinglayer 19 is etched, the capacitive film 70 remaining on a lower surfaceportion of the contact plug opening 67 may be removed to expose apartial surface of the fourth metal wiring 34 constituting the lowerelectrode 71. The etching of the capacitive film 70 is stopped at thefourth metal wiring 34. Thereafter, the resist 83 is removed.

Next, as shown in FIG. 3E, the barrier metal layer 43 and the electrodefilm 84 can be formed. The barrier metal layer 43 may be formed to coverthe surface (upper surface) of the ninth interlayer insulating layer 19,inner side walls of the plug openings 66, 67, and 68, and the surfacesof the upper electrode 72 exposed from a lower surface of the plugopening, the first metal film 41, and the lower electrode 71. After theformation of the barrier metal layer 43, an electrode film 84 is formed.The electrode film 84 may be made of a metallic material to constitutethe second metal film 42 of the fuse film 4 and the plug 9, and may bedeposited on the entire surface to completely fill the plug openings 66,67, and 68. The barrier metal layer 43 can be configured, for example,as a stacked film formed by stacking a Ta film, a TaN film, a Ti film,and a TiN film sequentially from a lower side, and may be formed bysequentially depositing those constituent films through a sputteringmethod. The electrode film 84 may be made of, for example, tungsten (W),and may be formed through CVD.

Next, as shown in FIG. 3F, the surface is planarized by, for example,CMP to remove the electrode film 84 outside the plug openings 66, 67,and 68. Accordingly, the second metal film 42 also serving as a fuseplug may be disposed within the fuse plug opening 66, and the contactplugs 91 and 92 (plugs for an interlayer connection) can be disposed inthe contact plug openings 67 and 68.

Thereafter, as shown in FIG. 1, the uppermost layer wiring 5 is formedto have a certain pattern, and the passivation film 3 covering theuppermost layer wiring 5 is formed. Additionally, the pad opening 46,the annular opening 48 on the sealing member 6, and the recess portion49 as a process window for cutting the fuse are formed by selectivelyetching the passivation film 3. In this manner, the semiconductor devicehaving the structure illustrated in FIG. 1 is obtained.

Thus, the upper electrode 72 of the capacitor 7 and the first metal film41 of the fuse film 4 can be formed through the same process, andfurther, the contact plugs 91 and 92 (plugs for an interlayerconnection) and the second metal film 42 of the fuse film 4 can beformed through the same process. Accordingly, the semiconductor devicehaving a structure capable of restraining or preventing a breakdown or adegradation of characteristics resulting from the fuse film 4 can befabricated through a smaller number of processes.

Further, the fuse plug opening 66 may be formed in a region within theformation region of the first metal film 41 when viewed from the plane,so etching for forming the fuse plug opening 66 can be stopped at thefirst metal film 41. Thus, a film thickness of the second metal film 42constituting the fuse film 4 can be accurately controlled. When thefirst metal film 41 is not formed, if etching conditions (overcoatetching amount) for the contact plug opening 67 are determined toreliably reach the fourth metal wiring 34, the fuse plug opening 66 maybecome deeper than a required film thickness of the fuse film 4.Therefore, the fuse film 4 has a film thickness that is more thannecessary. Thus, for example, when the fuse film is cut (fusion cutting)by laser processing, a required laser light output is increased.Meanwhile, in some embodiments, the first metal film 41 can bepreviously formed and the fuse plug opening 66 may be formed by usingthe first metal film 41 as an etching mask, so the film thickness of thesecond metal film 41 can be controlled to be a required sufficientthickness. Thus, the fuse film 4 can be cut (fusion cutting) by a laserof a low output in a short time.

More specifically, for example, when the thickness of the interlayerinsulating layer 19 of the plug formation layer 10 is 700 nm and theovercoat etching amount is 100 nm, if the first metal film 41 is notformed, the film thickness of the second metal film 42 is 800 nm(=700nm+100 nm). Meanwhile, when the thickness of the first metal film 41 is40 nm and the underlying capacitive film 70 is 80 nm, the thickness ofthe second metal film 42 is 580 nm(=700 nm-(80 nm+40 nm)). Thus, byforming the first metal film 41, the thickness of the second metal film42 made of, for example, tungsten (W), or the like, can become thinnerby 220 nm. Accordingly, cutting of the fuse film 4 through laserprocessing is facilitated.

FIG. 4 is a sectional view for illustrating the configuration of a majorpart of a semiconductor device according to some embodiments. Certainreference numerals used for certain elements illustrated in FIG. 1 andas described above correspond to the same elements in FIG. 4, and, inthe interest of brevity, a repeated description will be omitted forthese same elements.

In the semiconductor device of some embodiments, the fuse film 4 may beformed of the first metal film 41. A pair of fuse plugs 76 and 77 can beformed to be in contact with both end portions of the first metal film41, respectively. The uppermost layer wirings 51, 53, 52, and 54 may beformed to be in contact with the fuse plugs 76 and 77. The fuse plugs 76and 77 can be buried in fuse plug openings 78 and 79 formed in the ninthinterlayer insulating layer 19, respectively. The lower surface (surfaceof the first metal film 41) and a side wall (the side of the ninthinterlayer insulating layer 19) of the fuse plug openings 78 and 79 maybe covered by the barrier metal layer 43. The fuse plugs 76 and 77 maybe buried in the openings 78 and 79, respectively, such that they are incontact with the barrier metal layer 43. The fuse plugs 76 and 77 may bemade of, for example, tungsten (W). Further, the barrier metal layer 43may be configured, for example, as a stacked film formed by stacking aTa layer, a TaN layer, a Ti layer, and a TiN layer sequentially from alower side.

The fuse film 4 positioned immediately under the recess portion 49(window for fuse cutting) formed in the passivation film 3 may beconfigured by only the first metal film 41. Thus, cutting of the fusefilm 4 is facilitated as compared to the case of some embodimentspreviously described. Specifically, when the fuse film 4 is cut (fusioncutting) by laser processing, the fuse film 4 can be cut by a laser of alow output in a short time.

FIGS. 5A to 5C are sectional views for illustrating a process forfabricating the semiconductor device, according to some embodiments, inwhich a process after the contact plug opening is formed.

First, similar to the case of the semiconductor device of the foregoingfirst embodiment, the foregoing process described with reference toFIGS. 3A to 3C also apply to FIGS. 5A to 5C. Thus, in the interest ofbrevity, the same steps or components sharing the same referencenumerals will not be repeated.

As shown in FIG. 5A, a resist 86 having a pattern with openingscorresponding to the fuse plug openings 78 and 79 and the contact plugopenings 67 an 68 may be formed. The ninth interlayer insulating layer19 may be etched through etching using the resist 86 as a mask, andaccordingly, the fuse plug openings 78 and 79 and the contact plugopenings 67 and 68 penetrating the ninth interlayer insulating layer 19are formed. The fuse plug openings 78 and 79 are positioned within aninternal region of the first metal film 41 when viewed from the plane,and the contact plug opening 68 may be positioned within an internalregion of the upper electrode 72 when viewed from the plane. Thus,etching of the ninth interlayer insulating layer 19 is stopped at thefirst metal film 41 and the upper electrode 72. Further, etching of theninth interlayer insulating layer 19 in the region of the contact plugopening 67 is stopped at the capacitive film 70. That is, the firstmetal film 41, the upper electrode 72, and the capacitive film 70 serveas etching stop layers. After the ninth interlayer insulating layer 19is etched, the capacitive film 70 remaining at the lower surface portionof the contact plug opening 67 may be removed to expose a portion of thesurface of the fourth metal wiring 34 constituting the lower electrode71. Thereafter, the resist 86 is removed.

Next, as shown in FIG. 5B, the barrier metal layer 43 and the electrodefilm 84 are formed. The barrier metal layer 43 may be formed to coverthe surface (upper surface) of the ninth interlayer insulating layer 91,the inner walls of the plug openings 78, 79, 67, and 68, and thesurfaces of the upper electrodes 72, the first metal film 41, and thelower electrode 71 exposed from lower faces of these plug openings.After the formation of the barrier metal layer 43, an electrode film 84may be formed. The electrode film 84 can be made of a metallic materialto constitute the fuse plugs 76 and 77 and the plug 9, and may bedeposited on the entire surface to completely fill the plug openings 78,79, 67, and 68. The barrier metal layer 43 may be configured, forexample, as a stacked film formed by stacking a Ta film, a TaN film, aTi film, and a TiN film sequentially from a lower side, and may beformed by sequentially depositing those constituent films through asputtering method. The electrode film 84 may be made of, for example,tungsten (W), and may be formed through CVD.

Next, as shown in FIG. 5C, the surface can be planarized by, forexample, CMP to remove the electrode film 84 outside the plug openings78, 79, 67, and 68. Accordingly, the fuse plugs 76 and 77 are disposedwithin the fuse plug openings 78 and 79, and the contact plugs 91 and 92are disposed in the contact plug openings 67 and 68.

Thereafter, as shown in FIG. 1, the uppermost layer wiring 5 may beformed to have a certain pattern, and the passivation film 3 coveringthe uppermost layer wiring 5 is formed. Additionally, the pad opening46, the annular opening 48 on the sealing member 6, and the recessportion 49 as a process window for cutting the fuse are formed byselectively etching the passivation film 3. In this manner, thesemiconductor device having the structure illustrated in FIG. 4 isobtained.

FIG. 6 is a sectional view for illustrating the configuration of a majorpart of a semiconductor device, according to some embodiments. In FIG.6, the same reference numerals are used for the corresponding elementsas those illustrated in FIG. 1 as described above, and, in the interestof brevity, a repeated description will be omitted.

In the semiconductor device according to some embodiments, the fuse film4 may be formed of a metal film 44 equivalent to the second metal film41 of FIG. 1. The uppermost layer wirings 51, 53, 52, and 54 are formedto be in contact with the surfaces of both end portions of the metalfilm 44. The metal film 44 is buried in a fuse plug opening 80 formed inthe ninth interlayer insulating layer 19. A lower surface and a sidewall of the fuse plug opening 80 are covered by the barrier metal layer43. The metal film 44 is buried in the fuse plug opening 80 such that itis in contact with the barrier metal layer 43. The metal film 44 is madeof, for example, tungsten (W). Further, the barrier metal layer 43 isconfigured, for example, as a stacked film formed by stacking a Talayer, a TaN layer, a Ti layer, and a TiN layer sequentially from alower side.

The fuse film 4 positioned immediately under the recess portion 49(window for fuse cutting) formed in the passivation film 3 is configuredto include the metal film 44 and the barrier metal layer 43.

A lower surface of the fuse plug opening 80 is in contact with theeighth interlayer insulating layer 18. This is because the surface layerportion of the eighth interlayer insulating layer 18 is etched for anovercoat etching when the fuse plug opening 80 is formed. Further, aside wall of the fuse plug opening 80 is in contact with the eighthinterlayer insulating layer 18, the capacitive film 70, and the ninthinterlayer insulating layer 19 sequentially from a lower side, exposingthe side surfaces thereof. The metal film 44 buried in the fuse plugopening 80 has a film thickness greater than that of the second metalfilm 42 of FIG. 1.

FIGS. 7A to 7F are sectional views for illustrating a process offabricating the semiconductor device according to the third embodiment,in which a process after the formation of the capacitive film 70.

As shown in FIG. 7A, the fourth metal wiring 14 is buried in the eighthinterlayer insulating layer 18 and planarized (e.g., through CMP), andthen, the capacitive film 70 is formed on the planarized surface. Thecapacitive film 70 may be made of, for example, an insulating material,for example, SiN or SiCN, that can prevent copper (Cu) from spreading.The capacitive film 70 is formed to cover the surfaces of the eighthinterlayer insulating layer 18 and the fourth metal wiring 14 through,for example, plasma CVD. Thereafter, the electrode film 81 constitutingthe upper electrode 72 and the first metal film 41 is stacked on thecapacitive film 70. The electrode film 81 may be made of, for example,TiN, and formed through a sputtering method.

Next, as shown in FIG. 7B, the resist 82 having a pattern correspondingto the upper electrode 72 may be formed, and the electrode film 81 maybe etched by using the resist 82 as a mask. This etching is executeduntil the electrode film 81 in the region exposed from the resist 82 iscompletely removed. For this reason, in the region exposed from theresist 82, the capacitive film 70 not covered by the upper electrode 72is slightly etched (up to the middle of the film thickness).Accordingly, the upper electrode 72 is formed, and the capacitive film70 positioned immediately under the upper electrode 72 is relativelythick, and other regions become relatively thin. Thereafter, the resist82 is removed.

Next, as shown in FIG. 7C, the ninth interlayer insulating layer 19 maybe formed. The ninth interlayer insulating layer 19 may be made of, forexample, SiO₂, and may be formed through plasma CVD.

Next, as shown in FIG. 7D, a resist 83 having openings corresponding toa plug opening 80 for a fuse and contact plug openings 67 and 68 may beformed. The ninth interlayer insulating layer 19 may be etched by theetching using the resist 83 as a mask, and accordingly, the fuse plugopening 80 and the contact plug openings 67 and 68 penetrating the ninthinterlayer insulating layer 19 can be formed. The contact plug opening68 may be positioned in an internal region of the upper electrode 72when viewed from the plane. Thus, etching of the ninth interlayerinsulating layer 19 is stopped at the upper electrode 72. Further, inthe fuse plug opening 80 and the contact plug opening 67, etching of theninth interlayer insulating layer 19 is stopped at the capacitive film70. After the ninth interlayer insulating layer 19 is etched, thecapacitive film 70 remaining at a lower surface portion of the contactplug opening 67 may be removed to expose a partial surface of the fourthmetal wiring 34 constituting the lower electrode 71. This etching isstopped at the fourth metal wiring 34. Thereafter, the resist 83 isremoved.

The etching of the capacitive film 70 may also be performed at the fuseplug opening 80. Further, since the fourth metal wiring 34 is notinstalled immediately under the fuse plug opening 80, etching within thefuse plug opening 80 penetrates the capacitive film 70 to reach thesurface layer portion of the eighth interlayer insulating layer 18. Ifthis etching condition is not applied, the fourth metal wiring 34 cannotbe reliably exposed at the lower surface of the contact plug opening 67.

Next, as shown in FIG. 7E, the barrier metal layer 43 and the electrodefilm 84 can be formed. The barrier metal layer 43 may be formed to coverthe surface (upper surface) of the ninth interlayer insulating layer 19,inner side walls of the plug openings 80, 67, and 68, and the surfacesof the eighth interlayer insulating layer 18, the upper electrode 72,and the lower electrode 71 exposed from lower surfaces of these plugopenings 80, 67, and 68. After the formation of the barrier metal layer43, an electrode film 84 may be formed. The electrode film 84 can bemade of a metallic material to constitute the metal film 44 of the fusefilm 4 and the plug 9, and may be deposited on the entire surface tocompletely fill the plug openings 80, 67, and 68. The barrier metallayer 43 is configured, for example, as a stacked film formed bystacking a Ta film, a TaN film, a Ti film, and a TiN film sequentiallyfrom a lower side, and may be formed by sequentially depositing theconstituent films through a sputtering method. The electrode film 84 maybe made of, for example, tungsten (W), and may be formed through CVD.

Next, as shown in FIG. 7F, the surface is planarized by, for example,CMP to remove the electrode film 84 outside the plug openings 66, 67,and 68. Accordingly, the metal film 44 also serving as a fuse plug maybe disposed within the fuse plug opening 80, and the contact plugs 91and 92 can be disposed in the contact plug openings 67 and 68.

Next, as shown in FIG. 6, the uppermost layer wiring 5 is formed to havea certain pattern, and the passivation film 3 covering the uppermostlayer wiring 5 may be formed. And, the pad opening 46, the annularopening 48 on the sealing member 6, and the recess portion 49 as aprocess window for cutting the fuse are formed by selectively etchingthe passivation film 3. In this manner, the semiconductor device havingthe structure illustrated in FIG. 6 may be obtained.

Various embodiments have been described, but the present disclosure mayalso be implemented in other ways. For example, as indicated by the twopoint chain line in FIG. 4, the fuse film 4 may have the second metalfilm 42 separated from the fuse plugs 76 and 77. In some embodiments,the second metal film 42 is made of the same material on the same layer(plug formation layer 10) as that of the fuse plugs 76 and 77. Further,in the configuration of FIG. 4, the fuse plugs 76 and 77 may be widenedin a length direction of the fuse film 4 (horizontal direction in FIG.4) to protrude from the edge portions of the uppermost layer wiring 5towards the recess portion 49 (cutting process window).

Further, the number of wiring layers of the multilayer wiring structure2 is not limited to the foregoing embodiments, and the number of thewiring layers may be changed to a certain number or any reasonablenumber.

FIG. 8 is a sectional view for illustrating the configuration of a majorpart of a semiconductor device according to another embodiment. FIG. 9is a partial plan view of the configuration illustrated in FIG. 8. FIGS.10A to 10E are sectional views sequentially showing a process of amethod for fabricating the semiconductor device.

The semiconductor device illustrated in FIG. 8 includes a semiconductorsubstrate 1 _(—) a, a multilayer wiring structure 2 _(—) a formed on asurface of the semiconductor substrate 1 _(—) a, and a passivation film(surface protective film) 3 _(—) a covering the multilayer wiringstructure 2 _(—) a. The semiconductor substrate 1 _(—) a may be asilicon substrate, and a functional element (semiconductor element) (notshown) represented by an active element such as a transistor or the likeis formed on a surface layer portion of the semiconductor substrate 1_(—) a. The multilayer wiring structure 2 _(—) a includes interlayerinsulating films 11 _(—) a˜23 _(—) a, etching stop layers 31 _(—) a˜ 42_(—) a, copper wiring layers 51 _(—) a˜ 56 _(—) a, a fuse film 4 _(—) a(copper fuse), an uppermost layer wiring 5 _(—) a (a wiring film, anexternal connection layer), and the like. The passivation film 3 _(—) amay be formed of, for example, a nitride film (silicon nitride film) andcovers a surface of the uppermost layer wiring 5 _(—) a. In FIG. 9, anillustration of the passivation film 3 _(—) a is omitted.

In the present embodiment, the multilayer wiring structure 2 _(—) aincludes a copper sealing member 6 _(—) a formed to have a cylindricalshape (e.g., a square cylindrical or container-like shape) surroundingthe fuse film 4 _(—) a, and seal films 7 _(—) a and 8 _(—) a (copperseal films) having a flat plate-like shape disposed at a lower portionand a middle portion in a height direction of the copper sealing member6 _(—) a, respectively, when viewed from a plane. In the multilayerwiring structure 2 _(—) a, the interlayer insulating film 11 _(—) a, theetching stop layer 31 _(—) a, the interlayer insulating film 12 _(—) a,the etching stop layer 32 _(—) a, the interlayer insulating film 13 _(—)a, the etching stop layer 33 _(—) a, the interlayer insulating film 14_(—) a, the etching stop layer 34 _(—) a, the interlayer insulating film15 _(—) a, the etching stop layer 35 _(—) a, the interlayer insulatingfilm 16 _(—) a, the etching stop layer 36 _(—) a, the interlayerinsulating film 17 _(—) a, the etching stop layer 37 _(—) a, theinterlayer insulating film 18 _(—) a, the etching stop layer 38 _(—) a,the interlayer insulating film 19 _(—) a, the etching stop layer 39 _(—)a, the interlayer insulating film 20 _(—) a, the etching stop layer 40_(—) a, the interlayer insulating film 21 _(—) a, the etching stop layer41 _(—) a, the interlayer insulating film 22 _(—) a, the etching stoplayer 42 _(—) a, and the interlayer insulating film 23 _(—) a arestacked in this order, starting from the surface of the semiconductorsubstrate 1 _(—) a. The interlayer insulating films 11 _(—) a˜23 aremade of, for example, SiO₂. Further, the etching stop layers 31 _(—) a,33 _(—) a, 35 _(—) a, 37 _(—) a, 39 _(—) a, and 41 _(—) a are made of,for example, SiCN. The etching stop layers 32 _(—) a, 34 _(—) a, 36 _(—)a, 38 _(—) a, 40 _(—) a, and 42 _(—) a are formed of, for example, astacked film with SiC and SiCN.

Copper wiring layers 51 _(—) a (51 s _(—) a, 51 i _(—) a, 51 e _(—) a)are formed in the interlayer insulating film 12 _(—) a, copper wiringlayers 52 _(—) a (52 s _(—) a, 52 i _(—) a, 52 e _(—) a) are formed inthe interlayer insulating film 14 _(—) a, copper wiring layers 53 _(—) a(53 s _(—) a, 53 i _(—) a, 53 e _(—) a) are formed in the interlayerinsulating film 16 _(—) a, copper wiring layers 54 _(—) a (54 s _(—) a,54 i _(—) a, 54 e _(—) a) are formed in the interlayer insulating film18 _(—) a, copper wiring layers 55 _(—) a (55 s _(—) a, 55 i _(—) a, 55e _(—) a) are formed in the interlayer insulating film 20 _(—) a, andcopper wiring layers 56 _(—) a (56 s _(—) a, 56 i _(—) a, 56 e _(—) a)are formed in the interlayer insulating film 22 _(—) a. The copperwiring layers 51 _(—) a˜56 _(—) a are wirings (copper wirings) made ofan electrically conductive material including copper as a mainingredient. These copper wiring layers 51 _(—) a˜56 _(—) a are buried inwiring recesses respectively formed in the interlayer insulating films12 _(—) a, 14 _(—) a, 16 _(—) a, 18 _(—) a, 20 _(—) a, and 22 _(—) a.More specifically, the copper wiring layer 51 _(—) a is buried in thewiring recess formed in the interlayer insulating film 12 _(—) a by adamascene process. In addition, the copper wiring layers 52 _(—) a˜56_(—) a are buried in the wiring recesses respectively formed in theinterlayer insulating films 14 _(—) a, 16 _(—) a, 18 _(—) a, 20 _(—) a,and 22 _(—) a by a dual damascene process, and also buried in vias(holes) respectively formed in the interlayer insulating films 13 _(—)a, 15 _(—) a, 17 _(—) a, 19 _(—) a, and 21 _(—) a. Accordingly, thecopper wiring layers 52 _(—) a˜56 _(—) a are electrically connected tothe copper wiring layers 51 _(—) a˜55 _(—) a which are immediately belowthe copper wiring layers 52 _(—) a˜56 _(—) a, respectively.

A barrier metal layer 58 _(—) a is formed on inner wall surfaces of thewiring recesses and the vias in order to prevent the spread of copper.The copper wiring layers 51 _(—) a˜56 _(—) a including copper as a mainingredient are disposed in regions surrounded by the barrier metal layer58 _(—) a and the etching stop layers 32 _(—) a, 34 _(—) a, 36 _(—) a,38 _(—) a, 40 _(—) a, and 42 _(—) a. The etching stop layers 31 _(—) a,33 _(—) a, 35 _(—) a, 37 _(—) a, 39 _(—) a, and 41 _(—) a are layers forstopping etching which is performed on the interlayer insulating films12 _(—) a, 14 _(—) a, 16 _(—) a, and 18 _(—) a to form the wiringrecesses. Also, the etching stop layers 32 _(—) a, 34 _(—) a, 36 _(—) a,37 _(—) a, 38 _(—) a, and 40 _(—) a are layers for stopping etchingwhich is performed on the interlayer insulating films 13 _(—) a, 15 _(—)a, 17 _(—) a, 19 _(—) a, and 21 _(—) a to form the vias. The barriermetal layer 58 _(—) a is formed of a stacked film of, for example, a Talayer and a TaN layer, and the Ta layer is in contact with the copperwiring layer.

In this embodiment, the fuse film 4 _(—) a has a linear shape (band-likeshape) when viewed from a side cross sectional view. The fuse film 4_(—) a electrically connects the uppermost wirings 501 _(—) a and502(5)_(—) a. Specifically, the uppermost wiring 501 _(—) a (a firstconnection portion) is connected to one end (a first portion) of thefuse film 4 _(—) a, and the uppermost wiring 502 _(—) a (a secondconnection portion) is connected to the other end (a second portion) ofthe fuse film 4 _(—) a.

Both ends of the fuse film 4 _(—) a are electrically connected to theuppermost wirings 501(5)_(—) a and 502(5)_(—) a, respectively, throughplugs 9 _(—) a for connecting the uppermost wiring 5 _(—) a (upperwiring layer) to the underlying copper wiring layer 56 _(—) a (lowerwiring layer). The plug 9 _(—) a is made of metal buried in an openingformed in the uppermost interlayer insulating film 23 _(—) a. Morespecifically, openings (through-holes) corresponding to the plugs 9 _(—)a are formed in the interlayer insulating film 23 _(—) a. The innersurface (a lower surface and side wall surfaces) of the opening iscovered by a barrier metal layer 24 _(—) a. Then, the plug 9 _(—) a isburied in the opening surrounded by the barrier metal layer 24 _(—) a.The plug 9 _(—) a is made of, for example, an electrically conductivematerial, for example, tungsten (W), including a metallic material,other than copper, as a main ingredient. The barrier metal layer 24 _(—)a is a conductive layer having the properties of preventing the spreadof the material of the plug 9 _(—) a and the material of the fuse film 4_(—) a, and is configured as, for example, a stacked film formed bysequentially stacking Ta, TaN, Ti, and TiN, starting from the fuse film4 _(—) a.

The fuse film 4 _(—) a is formed by a portion of the copper wiring layer56 _(—) a formed at the uppermost layer among the copper wiring layers51 _(—) a˜56 _(—) a. More specifically, a recess corresponding to theshape of the fuse film 4 _(—) a is formed in the interlayer insulatingfilm 22 _(—) a corresponding to the copper wiring layer 56 _(—) a. Theinner wall surface (a lower surface and a side wall surface) of therecess is covered by the barrier metal layer 58 _(—) a, and a metallicmaterial (a metallic material including copper as a main ingredient)constituting the copper wiring layer 56 _(—) a is buried in the recesssurrounded by the barrier metal layer 58 _(—) a, constituting the fusefilm 4 _(—) a. Since the barrier metal layer 58 _(—) a that is incontact with the fuse film 4 _(—) a also contributes to the electricalconnection between the uppermost wirings 501 _(—) a and 502 _(—) a, thebarrier metal layer 58 _(—) a may be also regarded as a portion of thefuse film.

The uppermost wiring 5 _(—) a is a wiring film including, for example, amain body portion 5 a _(—) a, a barrier layer 5 b _(—) a stacked underthe main body portion 5 a _(—) a, and a surface metal film 5 c stackedon the main body portion 5 a _(—) a. The main body portion 5 a _(—) a ismade of a conductive material, e.g., AlCu, including a metal (e.g.,aluminum), other than copper, as a main ingredient, and the barrierlayer 5 b _(—) a is configured as, for example, a stacked film formed bysequentially stacking Ti and TiN from the bottom.

As shown in FIG. 9, the copper sealing 6 _(—) a is formed to have acylindrical shape (a square container-like shape in this embodiment)surrounding the fuse film 4 _(—) a when viewed from a sidecross-sectional view, and configured by the copper wiring layers 51 _(—)a˜56 _(—) a. Hereinafter, the copper wiring layers 51 _(—) a˜56 _(—) aconstituting the copper sealing member 6 _(—) a will be referred to ascopper wiring layers 51 s _(—) a˜56 s _(—) a or the like. Among thecopper wiring layers constituting the copper sealing member 6 _(—) a,the copper wiring layers 52 s _(—) a, 53 s _(—) a, 55 s _(—) a, and 56 s_(—) a have an annular shape (a square annular shape in this embodiment)and overlap with each other when viewed from the plane. Also, among thecopper wiring layers constituting the copper sealing member 6 _(—) a,the lowermost copper wiring layer 51 s _(—) a and the copper wiringlayer 54 s _(—) a positioned above the lowermost copper wiring 51 s _(—)a with an interval corresponding to two cooper wiring layers in thisembodiment) therebetween are formed in a solid shape (a square shape inthis embodiment) having an outline corresponding to the container-likeshape of the copper sealing member 6 _(—) a when viewed from a sidecross-sectional view. An annular portion (a square annular portion inthis embodiment) of the circumference of the copper wiring layers 51 s_(—) a and 54 s _(—) a constitute a portion of the copper sealing member6 _(—) a. Further, in the copper wiring layers 51 s _(—) a and 54 s _(—)a, a central portion continued to the interior of the annular portionconstitutes the seal films 7 _(—) a and 8 _(—) a interposed between thefuse film 4 _(—) a and the semiconductor substrate 1 _(—) a. In thisembodiment, the copper sealing member 6 _(—) a and the seal films 7 _(—)a and 8 _(—) a are integrated. That is, the copper sealing member 6 _(—)a and the seal films 7 _(—) a and 8 _(—) a are coupled without a gaptherebetween.

The upper seal film 8 _(—) a is positioned below the fuse film 4 _(—) awith an interval (corresponding to the wiring layer of the copper wiringlayer 55 _(—) a) therebetween from the fuse film 4 _(—) a. Further, theseal films 7 _(—) a and 8 _(—) a are formed such that the fuse film 4_(—) a fits into the inner side of the outer circumference of the sealfilms 7 _(—) a and 8 _(—) a when viewed from a side cross-sectionalview. Annular vias 62 _(—) a˜66 _(—) a are formed to have an annularshape corresponding to the planar shape of the copper sealing member 6_(—) a below the copper wiring layers 52 s _(—) a˜56 s _(—) aconstituting the copper sealing member 6 _(—) a. The copper wiringlayers 52 s _(—) a˜56 s _(—) a are formed so as to fill the annular vias62 _(—) a˜66 _(—) a directly below the copper wiring layer 52 s _(—)a˜56 s _(—) a. Thus, a hermetically closed space surrounded by thecopper wiring layers 51 s _(—) a˜54 s _(—) a and a semi-hermeticallyclosed space surrounded by the copper wiring layers 54 s _(—) a˜56 s_(—) a are formed at the inner side of the copper sealing 6 _(—) a. Thefuse film 4 _(—) a is disposed in the semi-hermetically closed space (atan upper end position of the corresponding space in this embodiment).

Meanwhile, the uppermost wiring 502 _(—) a electrically connected to oneend of the fuse film 4 _(—) a extends to an outer side of the coppersealing member 6 _(—) a when viewed from a side cross sectional view.Further, in the outer side the copper sealing member 6 _(—) a, theuppermost wiring 502 _(—) a is electrically connected to an element(e.g., a transistor element) 25 _(—) a formed on the semiconductorsubstrate 1 _(—) a through the copper wiring layers 51 _(—) a˜56 _(—) a(which are called copper wiring layers 51 _(—) ai˜56 i _(—) a or thelike, hereinafter) constituting an internal connection circuit 71 _(—)a. More specifically, the uppermost wiring 502 _(—) a is connected tothe copper wiring layer 56 i _(—) a through the plug 9 _(—) a formedoutside the copper sealing 6 _(—) a. The copper wiring layer 56 i _(—) ais connected to the underlying copper wiring layer 55 i _(—) a, which isfurther connected to the underlying copper wiring layer 54 i _(—) a. Ina similar structure, the copper wiring layer 56 i _(—) a is connected tothe lowermost copper wiring layer 51 _(—) ai. Also, the copper wiringlayer 51 _(—) ai is bonded to a metal plug 27 buried in the via 26 _(—)a which is formed in the interlayer insulating film 11 _(—) a. In thisembodiment, the metal plug 27 _(—) a is connected to a polysiliconwiring layer 28 _(—) a formed on the semiconductor substrate 1 _(—) a.The polysilicon wiring layer 28 _(—) a may constitute, for example, agate electrode of the element 25 _(—) a formed on the semiconductorsubstrate 1 _(—) a. The metal plug 27 _(—) a is made of, for example,tungsten (W). A barrier metal layer 29 _(—) a (which is made of, forexample, Ta) is interposed between the metal plug 27 _(—) a and theinterlayer insulating film 11 _(—) a.

In the multilayer wiring structure 2 _(—) a, outside the copper sealingmember 6 _(—) a, there is an external connection circuit 72 _(—) a(which includes, for example, the copper wiring layers 55 e _(—) a and56 e _(—) a) for connection with the outside of the semiconductordevice. The copper wiring layer 56 e _(—) a (56 _(—) a) constituting aportion of the external connection circuit 72 _(—) a is connectedthrough the plug 9 _(—) a to the uppermost wiring 503(5)_(—) a as anexternal connection layer. An opening 46 _(—) a for electricalconnection (e.g., connection through wire bonding) to the surface of theuppermost wiring 503(5)_(—) a is formed in the passivation film 3 _(—)a. A portion exposed from the opening 46 _(—) a in the uppermost wiring5 _(—) a is a pad 47 _(—) a for electrical connection with the outside.Further, a concave portion 49 _(—) a formed by thinning the passivationfilm 3 _(—) a is formed at a region (a square region across the middleregion of the fuse film 4 _(—) a in this embodiment) including animmediately upper portion of a middle portion of the fuse film 4 _(—) a.The concave portion 49 _(—) a may be simultaneously formed in an etchingprocess for forming the opening 46 _(—) a. The concave portion 49 _(—) ais used as, for example, a cutting process window when the fuse film 4_(—) a is cut (fused) through laser machining.

In this manner, in the semiconductor device, the seal films 7 _(—) a and8 _(—) a made of copper films are formed between the semiconductorsubstrate 1 _(—) a and the fuse film 4 _(—) a made of a copper film, andalso, the fuse film 4 _(—) a is surrounded by the cylindrical coppersealing member 6 _(—) a coupled to the seal films 7 _(—) a and 8 _(—) a.Thus, the fuse film 4 _(—) a is surrounded by the seal films 7 _(—) aand 8 _(—) a and the copper sealing member 6 _(—) a at a lower side (thesemiconductor substrate 1 _(—) a side) and a lateral side of the fusefilm 4 _(—) a. For this reason, although copper fragments scatter whenthe fuse film 4 _(—) a is cut, the spread of copper atoms can be stoppedby the seal films 7 _(—) a and 8 _(—) a and/or the copper sealing member6 _(—) a. Accordingly, since the spread of the copper atoms in ahorizontal direction and a downward direction can be restrained, thecopper atoms can be restrained or prevented from reaching the vicinityof the surface of the semiconductor substrate 1 _(—) a. Thus, thefunctional element (the active element represented by a transistor, orthe like) formed on the semiconductor substrate 1 _(—) a can berestrained or prevented from being broken down or deteriorated in itsoperational characteristics (e.g., withstand voltage).

Further, the fuse film 4 _(—) a is connected to the uppermost wirings501 _(—) a and 502 _(—) a made of metal material films other than copperand formed above the fuse film 4 _(—) a. If the fuse film 4 _(—) a isnot cut, the uppermost wirings 501 _(—) a and 502 _(—) a areelectrically connected, and if the fuse film 4 _(—) a is cut, theelectrical connection between the uppermost wirings 501 _(—) a and 502_(—) a are cut off. In this manner, it is possible to adjust thecharacteristics of the electronic circuit that is built into thesemiconductor device, or disconnect the defects in the semiconductordevice.

The fuse film 4 _(—) a is connected to the internal connection circuit71 through the uppermost wiring 502 _(—) a. As such, since the fuse film4 _(—) a can be connected to the internal circuit of the semiconductordevice through the upper wiring layer, there is no need to form a wiringportion for connecting the fuse film 4 _(—) a to the circuit between thefuse film 4 _(—) a and the semiconductor substrate 1 _(—) a. Thus, thelower surface of the fuse film 4 _(—) a (between the fuse film 4 _(—) aand the semiconductor substrate 1 _(—) a) can be covered by the sealfilms 7 _(—) a and 8 _(—) a, and also, the seal films 7 _(—) a and 8_(—) a and the copper sealing member 6 _(—) a can be combined inseamless manners. Accordingly, the spread of the copper atoms to thesurface of the semiconductor substrate 1 _(—) a can be restrained orprevented when connecting the fuse film 4 _(—) a to the internalconnection circuit 71. If the connection to the internal connectioncircuit 71 is intended to be achieved only in the wiring layer lowerthan the fuse film 4 _(—) a, the lower side and the lateral side of thefuse film 4 _(—) a cannot be completely covered, resulting in a failureof avoiding the spread of copper atoms toward the surface of thesemiconductor substrate 1 _(—) a.

In addition, in this embodiment, the uppermost wiring 5 _(—) a to whichthe fuse film 4 _(—) a is connected and the plug 9 _(—) a between theuppermost wiring 5 _(—) a and the fuse film 4 _(—) a are made ofmetallic material film other than copper. Thus, corrosion from the cutsurface of the fuse film 4 _(—) a is stopped at the corresponding plug 9_(—) a and/or the uppermost wiring 5 _(—) a. Accordingly, since nocorrosion reaches the vicinity of the surface of the semiconductorsubstrate 1 _(—) a, a breakdown of the functional element formed on thesemiconductor substrate 1 _(—) a or deterioration in the operationalcharacteristics of the functional element can be restrained orprevented.

Further, for example, when the fuse film 4 _(—) a is cut by laser light,laser light can be reflected from the seal film 8 _(—) a toward the fusefilm 4 _(—) a. Accordingly, energy of laser light can be effectivelyused to cut the fuse film 4 _(—) a. Therefore, since less laser energymay be used for cutting (fusing) the fuse film 4 _(—) a, the fuse film 4_(—) a can be cut by a laser with low output in a short time. The sealfilm 8 _(—) a covering the fuse film 4 _(—) a from the lower side isformed to have a larger area than that of the fuse film 4 _(—) a, so theseal film 8 _(—) a is not easily heated even when irradiated with laserlight. Thus, the fuse film 4 _(—) a can be cut without damaging the sealfilm 8 _(—) a.

In addition, in this embodiment, the fuse film 4 _(—) a is connected tothe internal connection circuit 71 through the uppermost wiring 502 _(—)a formed in the same layer as that of the uppermost wiring 503 _(—) afor an external connection. Thus, the semiconductor device including thefuse film 4 _(—) a made of a copper film can be fabricated through asmaller number of fabrication processes. Also, the fuse film 4 _(—) a isformed in the same layer as the uppermost copper wiring layer 56 _(—) a.Therefore, for example, a small amount of energy can be used when thefuse film 4 _(—) a is cut by laser light. In addition, since thedistance from the semiconductor substrate 1 _(—) a to the fuse film 4_(—) a can be increased, the influence on the element formed on thesemiconductor substrate 1 _(—a) can be further restrained.

FIGS. 10A to 10E are sectional views sequentially illustrating theprocesses of a method for fabricating the semiconductor deviceillustrated in FIG. 8, which specifically show the processes after aformation of the copper wiring layer 54 _(—) a. As shown in FIG. 10A,the copper wiring layer 54 _(—) a including the seal film 8 _(—) a isformed on the interlayer insulating film 17 _(—) a (the first interlayerinsulating film) by a dual-damascene process. More specifically, theinterlayer insulating film 17 _(—) a, the etching stop layer 37 _(—) a,and the interlayer insulating film 18 _(—) a are stacked. Thereafter, awiring recess that penetrates the interlayer insulating film 18 _(—) aand the etching stop layer 37 _(—) a is formed in a position where thecopper wiring layer 54 _(—) a (including the seal film 8 _(—) a) isdisposed. Further, a via that penetrates the interlayer insulating film17 _(—) a and the etching stop layer 36 _(—) a is formed where the via(including the annular via 64 _(—) a) directly below the copper wiringlayer 54 _(—) a is disposed. Etching for forming the wiring recess inthe interlayer insulating film 18 _(—) a is stopped by the etching stoplayer 37 _(—) a. Thereafter, the etching stop layer 37 _(—) a on thebottom surface of the corresponding wiring recess is opened. Further, avia is formed by etching the interlayer insulating film 17 _(—) adirectly below the wiring recess. The etching for forming the via isstopped by the etching stop layer 36 _(—) a. Thereafter, etching isperformed to open the etching stop layer 36 _(—) a at a bottom surfaceof the via. And then, the barrier metal layer 58 _(—) a is formed on thesurface of the wiring recess, an inner wall surface of the via, and thesurface of the interlayer insulating film 18 _(—) a, and a copper filmis formed to coat the barrier metal layer 58 _(—) a. Then, the copperfilm and the barrier metal layer 58 _(—) a are planarized through achemical mechanical polishing (CMP) method until the surface of theinterlayer insulating film 18 _(—) a is exposed, such that the copperfilm and the barrier metal layer 58 _(—) a remain only within the wiringrecess and the via. Accordingly, the structure illustrated in FIG. 10Ais obtained. Although not shown, the copper wiring layers 51 _(—) a˜53_(—) a (including the seal film 7 _(—) a) are also formed through thesame process.

Thereafter, the same dual-damascene process is repeatedly performed tothereby stack the interlayer insulating films 19 _(—) a˜21 _(—) a (thesecond interlayer insulating films) on the seal film 8 _(—) a and formthe fuse film 4 _(—) a thereon, as shown in FIG. 10B. Further, at thesame time, the cylindrical copper sealing member 6 _(—) a is formed tosurround the fuse film 4 _(—) a and be coupled to the seal film 8 _(—) athrough the interlayer insulating films 19 _(—) a˜21 _(—) a when viewedfrom a side cross-sectional view.

Next, as shown in FIG. 10C, the interlayer insulating film 23 _(—) a isformed. The interlayer insulating film 23 _(—) a is made of, forexample, SiO₂, and may be formed through a plasma CVD method. Then, aresist 81 _(—) a having a pattern with an opening corresponding to acontact hole 75 _(—) a for the plug 9 _(—) a is formed. The interlayerinsulating film 23 _(—) a is etched through etching using the resist 81_(—) a as a mask, and accordingly, the contact hole 75 _(—) a thatpenetrates the interlayer insulating film 23 _(—) a is formed. Etchingfor forming the contact hole 75 _(—) a is stopped at the wiring layer 56_(—) a (including the fuse film 4 _(—) a). After the formation of thecontact hole 75, the resist 81 _(—) a is removed.

Next, as shown in FIG. 10D, the barrier metal layer 24 _(—) a and anelectrode film 82 are formed. The barrier metal layer 24 _(—) a isformed to cover the surface (the upper surface) of the interlayerinsulating film 23 _(—) a, the inner side wall of the contact hole 75_(—) a, and the surface of the copper wiring layer 56 _(—) a exposedfrom the lower surface of the contact hole 75 _(—) a. After theformation of the barrier metal layer 24 _(—) a, an electrode film 82_(—) a is formed. The electrode film 82 _(—) a is made of metallicmaterial to be used for constituting the plug 9 _(—) a and is depositedon the entire surface to fill the contact hole 75 _(—) a. The barriermetal layer 24 _(—) a is configured as, for example, a stacked filmformed by sequentially stacking a Ta film, a TaN film, a Ti film, and aTiN film, from the lower side, and may be formed by sequentiallydepositing the constituent films through a sputtering method. Theelectrode film 82 _(—) a is made of, for example, tungsten (W) and maybe formed through a CVD method.

Next, as shown in FIG. 10E, the surface is planarized by, for example, aCMP method, and the electrode film 82 _(—) a outside the contact hole 75_(—) a is removed. In this manner, the plug 9 _(—) a is disposed withineach contact hole 75 _(—) a. Thereafter, the uppermost wiring 5 _(—) ais formed to have a certain pattern as shown in FIG. 8, and thepassivation film 3 _(—) a covering the uppermost wiring 5 _(—) a isformed. And, the passivation film 3 _(—) a is selectively etched to formthe opening 46 _(—) a for the pad and the concave portion 49 _(—) a as afuse processing window. In this manner, the semiconductor device havingthe structure shown in FIG. 8 is obtained.

One embodiment of the present disclosure has been described so far, butanother embodiment may be implemented. For example, in the foregoingembodiment, the case in which the two sheets of seal films 7 _(—) a and8 _(—) a are formed between the fuse film 4 _(—) a and the semiconductorsubstrate 1 _(—) a is described as an example, but the lower seal film 7_(—) a may be omitted or the upper seal film 8 _(—) a may be omitted todispose a sheet of seal film between the semiconductor substrate 1 _(—)a and the fuse film 4 _(—) a. In case of omitting the lower seal film 7_(—) a, a portion lower than the seal film 8 _(—) a may be omitted inthe copper sealing member 6 _(—) a. This means that it does notnecessarily require a lot of wiring layers between the fuse film 4 _(—)a and the semiconductor substrate 1 _(—) a. Thus, even in asemiconductor device having a multilayer wiring structure with lessnumber of layers, it is possible to provide the copper fuse whileavoiding the deterioration of the characteristics of the element formedon the semiconductor substrate. In addition, in case of omitting thelower seal film 7 _(—) a, a wiring for forming a circuit at a lowerregion of the seal film 7 _(—) a may be provided. Of course, besides theseal films 7 _(—) a and 8 _(—) a, an extra seal film may also be added,and three or more sheets of seal films may be disposed between the fusefilm 4 _(—) a and the semiconductor substrate 1 _(—) a.

Further, in the foregoing embodiment, the case in which the element 25is formed outside the copper sealing member 6 _(—) a when viewed fromthe plane is taken as an example, but the element 25 may be formedinside the copper sealing member 6 _(—) a. The seal films 7 _(—) a and 8_(—) a interposed between the fuse film 4 _(—) a and the semiconductorsubstrate 1 _(—) a can restrain or prevent the spread of copper atomstoward the element formed inside the copper sealing member 6 _(—) a. Inthis manner, by disposing the element also inside the copper sealingmember 6 _(—) a, the degree of element integration can be increased.

Moreover, in the foregoing embodiments, the case in which the sealingmember 6 is formed to have the square container-like shape is taken asan example, but the sealing member 6 may have a container-like shapewith a lower surface having a polygonal shape other than a square shapeor may have any other container-like shapes such as a cylindrical shape,an oval cylindrical shape, or the like. Various design modifications maybe made within the scope of the claim coverage.

Moreover, in the foregoing embodiments, the case in which the sealingmember 6 is formed to have the square container-like shape is taken asan example, but the sealing member 6 may have a container-like shapewith a lower surface having a polygonal shape other than a square shapeor may have any other container-like shapes such as a cylindrical shape,an oval cylindrical shape, or the like.

Various design modifications may be made within the scope of the claimcoverage.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the subject matter described hereinmay be embodied in a variety of other forms or in any combination;furthermore, various omissions, substitutions and changes in the form ofthe embodiments described herein may be made without departing from thespirit of the disclosures. The accompanying claims and their equivalentsare intended to cover such forms or modifications as would fall withinthe scope and spirit of the disclosures.

1. A semiconductor device, comprising: a lower wiring layer made of aconductive material including copper; an upper wiring layer formed in anupper layer relative to the lower wiring layer; and a fuse film, atleast a portion of the fuse film being formed in a plug formation layerin which a plug configured to connect the lower wiring layer and theupper wiring layer is formed.
 2. The semiconductor device of claim 1,wherein the fuse film includes a conductive material that includes ametallic material other than copper.
 3. The semiconductor device ofclaim 1, further comprising: a fuse plug formed in the plug formationlayer configured to connect the fuse film and the upper wiring layer,the fuse plug being configured to include a conductive materialincluding a metallic material other than copper.
 4. The semiconductordevice of claim 1, further comprising: a capacitor being formed by alower electrode layer, an insulating layer, and an upper electrode layerbeing stacked, wherein the upper electrode layer is configured as ametallic layer in an upper layer relative to the lower wiring layer, andwherein the fuse film includes a first metal layer made of the samematerial as that of the upper electrode layer, the first metal layerbeing in a same layer as the upper electrode layer.
 5. The semiconductordevice of claim 1, wherein the fuse film comprises a second metal layerincluding the same material as that of the fuse plug, the second metallayer being in a same layer as the fuse plug.
 6. The semiconductordevice of claim 5, wherein the fuse plug and the second metal layer areintegrally formed.
 7. The semiconductor device of claim 1, furthercomprising: a sealing member formed to have a container-like shape tosurround the fuse film when viewed from a plane of the semiconductordevice.
 8. A method for fabricating a semiconductor device, comprising:forming a lower wiring layer made of a conductive material includingcopper; forming a plug formation layer on the lower wiring layer;forming a fuse film made of a conductive film including a metal otherthan copper, in the plug formation layer; forming an opening for aninterlayer connection plug and an opening for a fuse plug in the plugformation layer; burying a conductive material that includes a metalother than copper in the opening for the interlayer connection plug andthe opening for the fuse plug, and coupling the fuse plug to the fusefilm; and forming an upper wiring layer connected to the fuse plug andthe interlayer connection plug in an upper layer than the plug formationlayer.
 9. The method of claim 8, wherein the forming the fuse filmcomprises forming a capacitor structure including a lower electrodefilm, an insulating film, and an upper electrode film at an upper layerthan the lower wiring layer, and simultaneously forming a first metallayer made of the same metallic material as that of the upper electrodefilm in a same layer as the upper electrode film.
 10. The method ofclaim 8, wherein an opening for forming the fuse film is simultaneouslyformed when forming the opening for the interlayer connection plug andthe opening for the fuse plug, and wherein the burying the conductivematerial comprises forming a second metal layer by burying a metalhaving the same material as that of the interlayer connection plug inthe opening for forming the fuse film such that the second metal layerconstitutes at least a portion of the fuse film.
 11. A semiconductordevice, comprising: a semiconductor substrate; a copper fuse; a sealinglayer disposed between the semiconductor substrate and the copper fuse,the sealing layer being made of a copper layer; a wiring layer formed onan upper layer than the copper fuse, the wiring layer having a firstportion and a second potion which are connected to a first portion and asecond portion of the copper fuse, respectively, the wiring layer beingmade of a metallic layer that includes a metallic material other thancopper; and a copper sealing member coupled to the sealing layer andformed to have a container-like shape to surround the copper fuse. 12.The semiconductor device of claim 11, further comprising an externalconnection layer formed in a same layer as the wiring layer, theexternal connection layer being made of the same material as that of thewiring layer.
 13. The semiconductor device of claim 11, furthercomprising a plurality of copper wiring layers, wherein the copper fuseis formed in a same layer an uppermost layer among the plurality ofcopper wiring layers.